This invention relates to test equipment for semiconductor devices and more particularly to an improvde semiconductor burn-in socket assembly board test device.
In the past, semiconductor circuits were tested by "burn-in" on parallel pin boards. More recently, however, United States Government specifications (Mil. 883C), required that all burn-in boards have resistor isolation for reducing output and input interference between adjacent semiconductor devices being tested by burn-in.
Resistor isolation has been accomplished by laying several quarter-watt resistors (for example) along the sides of the sockets one for each pin. Each resistor used in this procedure occupies about 0.4 inches space when used in the horizontal position. To conserve some of this space, the resistor's have been used in a stand-up (hair pin like) position. When used in this fashion, horizontal space is preserved at the expense of increasing the vertical height. The disadvantage attending the use of stand-up resistors, is that they can be bent and bending causes the cracking of their bodies and shorts.
An example of a prior art burn-in socket having resistors attached to the contacts of the sockets with the resistors brought to the outside of the socket and secured to holes of the circuit board is the dual-in line package (DIP) burn-in socket disclosed in U.S. Pat. No. 4,478,476.
Another example of a prior art burn-in socket assembly for multi-pin integrated circuits (DIPs) includes a resistor located in a recess along a longitudinal axis of the socket assembly. In this arrangement, described in more detail in U.S. Pat. No. 4,428,633, the resistor is inserted directly into a socket housing with resistor body positioned into a longitudinal cavity. The resistor leads are gripped by walls of slots formed in the conductive material in contact with a tab connected to the printed circuit board.
In another electronic device, constituting the subject matter of U.S. Pat. No. 4,326,765, a carrier receives the leads of inserted integrated circuit devices and connects to a printed wiring circuit board. A recessed area of the carrier is provided for a resistor. Contact between the resistors and the circuit board pins is provided by arcurate spring members positioned within the body of the carrier. The pin members of the leads of the integrated circuit bias against the arcurate spring and extend into a socket contact electrically connected to the circuit board.